Latest News

January 28, 2017
Our paper “Surface Potential Equation for Low Effective Mass Channel Common Double-Gate MOSFET” has been accepted for publication in IEEE Transactions on Electron Devices. In this paper we propose a compact analytical solution for the coupled Poisson-Schrodinger system including Fermi-Dirac distribution, wave function penetration in gate oxide and asymmetry in gate oxide thickness.

June 8, 2016
Our paper “Atomistic modeling of the metallic-to-semiconducting phase boundaries in monolayer MoS2 has been accepted for publication in Applied Physics Letters. In this letter, interfacing the 2H and 1T’ polytypes of MoS2 appropriately, we first model the ‘beta’ and ‘gamma’ phase boundaries, and demonstrate good agreement with experiential results. We then apply density functional theory along with non equilibrium Green’s function(NEGF) formalism to asses the electronic property of the Schottky barrier at the phase boundaries.

Our paper “Theoretical Insights on the electro-thermal transport properties of monolayer MoS2 with line defects” has been accepted for publication in Journal of Applied Physics. In this work we use density functional theory and parameterised analytic potential coupled with quantum transport equations to study the electron and phonon transport in presence of line defects in monolayer MoS2.

March 2, 2016

Anuja Chanana has recieved Sarukkai Jagannathan Award 2015. It is given to the best performing PhD students of electrical science division based on their publication records and CGPA.

February 24, 2016

Our paper “Density Functional Theory based Study of Chlorine Doped WS2-metal Interface” has been accepted for publication in Applied Physics Letters. In this work we investigate the modulation of electronic structure of monolayer WS2 with chlorine doping and the related change in charge transfer when interfaces are formed with gold and palladium.

January 14, 2016

Our paper “Analytical Insight into the Lattice Thermal Conductivity and Heat Capacity of Monolayer MoS2” has been accepted for publication in Physica E.

Our paper “Prospects of Zero Schottky Barrier Height in a Graphene Inserted MoS2-Metal Interface” has been accepted for publication in Journal of Applied Physics. In this paper we employ Density Function Theory to understand the Schottky Barrier Height modulation in a MoS2-Metal Interface when graphene is inserted between them.

December 8, 2015

We received SERB-DST funding to conduct research on hetero-atomic-layer transistors.

November 23, 2015

Dr. Ramkrishna Ghosh has received the Tag Corporation Medal 2015, which is given for the best PhD thesis from the department every year. His work involved analysing real and complex band structure of 2D materials for nano-scale transistor applications. He is presently working as a Post-Doc fellow at University of Notre Dame.

Biswapriyo Das (M.Tech IIEST) and Chethan Kumar (M.E. IISc) have joined our group as PhD students.

July 13, 2015

Our paper “Compact noise modeling for common double gate MOSFET adapted to gate oxide thickness asymmetry” has been accepted for publication in IET Circuits, Devices & Systems. In this paper, based on the quasi-linear relationship between the surface potentials of a common double gate (CDG) MOSFET, we propose a compact model for thermal and flicker noise , which is adapted to gate-oxide thickness asymmetry.

July 11, 2015

Chethan Kumar and Dr. Neha Sharan received best paper award for the paper “indDG: A New Compact Model for Common Double Gate MOSFET adapted to Gate Oxide Thickness Asymmetry” in IEEE CONECCT 2015.

May 13, 2015

Our paper “Theoretical Insights to Niobium Doped Monolayer MoS2-Gold Contact” has been accepted for publication in the IEEE Transactions on Electron Devices. In this paper we report a first principles study of the electronic properties for a contact formed between Nb doped mono layer MoS2 and Gold for different doping concentrations. By careful examination of projected bandstructure, projected density of states,effective potential and charge density difference, we demonstrate that the Schottky barrier nature observed for pure MoS2-Au contact can be converted from n-type to p-type by efficient Nb doping.

May 12, 2015

Dr. Neha Sharan has joined TSMC, Taiwan as Principal Engineer.

February 2, 2015

Dr. Rekha Verma received the prestigious TechnoInventor Award 2014 from India Electronics and Semiconductor Association (IESA) for her PhD thesis. She worked on the theory and analytical modelling of thermoelectric properties of carbon nanomaterials.

January 31, 2015

Our paper “Phonon scattering limited performance of monolayer MoS2 and WSe2 n-MOSFET” has been accepted for publication in AIP Advances. In this paper through Ab-initio simulation coupled with NEGF formalism we show how the performance of monolayer TMD based MOSFET gets limited by phonon-scattering beyond the ballistic limit.

December 19, 2014

Neha Sharan has defended her PhD thesis successfully. She worked on the compact modeling of short channel asymmetric double gate MOSFETs.

December 8, 2014

Dr. Rekha Verma has joined IIIT Allahabad as an Assistant Professor.

November 6, 2014

Our paper “First Principles Study of Metal Contacts to Monolayer Black Phosphorous” has been accepted for publication in Journal of Applied Physics. In this paper, for the first time, by DFT, we study the ohmic nature of the contact formed between the new 2D material ‘Phosphorene’ with Gold, Palladium and Titanium.

October 28, 2014

Our paper “Monolayer Transition Metal Dichalcogenide Channel-Based Tunnel Transistor”, which is enlisted within top ten popular articles of IEEE J-EDS since Jan 2014, has found citation in Nature Nanotechnology (DOI: 10.1038/NNANO.2014.207). It is cited as: “In the absence of experimental results, the projected TFET performance for 2DMs (Fig. 4d) is based on simulations by Ghosh and Mahapatra and by Zhang and colleagues. These simulations provide the first estimates of the potential of 2DM-based TFETs with respect to the state-of-the-art devices.”

October 16, 2014

Our paper “Effect of line defects on the electrical transport properties of monolayer MoS2 sheet” has been accepted for publication in IEEE Transactions on Nanotechnology. In this work we present a DFT based computational study on the impact of line defects on the electronic properties of monolayer MoS2. Four different kinds of line defects with Mo and S as the bridging atoms, consistent with recent theoretical and experimental observations are considered herein. Our simulations show a 2-4 folds decrease in carrier conductance of MoS2 sheets in the presence of line defects as compared to that for the perfect sheet.

September 14, 2014

Our paper “A Continuous Electrical Conductivity Model for Monolayer Graphene from Near Intrinsic to Far Extrinsic Region” has been accepted for publication in the IEEE Transactions on Electron Devices. In this paper we present a physically based closed form continuous model for the electrical conductivity of a single layer graphene (SLG), validity of which extends from chemical potential close to the Dirac cone vertex to very far from it. Previous models were valid only at the asymptotic regimes.

September 9, 2014

Ms. Neha Sharan has submitted her PhD thesis for evaluation. She worked on the compact modeling of short channel common double gate MOSFET adapted to gate-oxide thickness asymmetry. Her works have resulted in several journal and conference publications.

Our paper “Impact of Stone-Wales and lattice vacancy defects on the electro-thermal transport of the free standing structure of metallic ZGNR” has been accepted for publication in Journal of Computational Electronics (Springer). In this paper using atomistic simulation we study the effect of Stone-Wales and lattice vacancy defects on the electro-thermal transport properties of zigzag graphene nanoribbon at their ballistic limits.

June 14, 2014

Our paper “A Short Channel Common Double Gate MOSFET Model Adapted to Gate Oxide Thickness Asymmetry” has been accepted for publications in IEEE Transactions on Electron Devices. In this paper the unique quasi-linear surface potential relationship is used to include the drain induced barrier lowering (DIBL), channel length modulation (CLM), velocity saturation and quantum mechanical effect (QME) in the core of indDG model.

June 12, 2014

Prof. Mahapatra has joined the editorial board of IETE Technical Review, a journal from The Institution of Electronics and Telecommunication Engineers, India.

June 4, 2014

Dr. Sitangshu Bhattacharya has joined IIIT Allahabad as an Assistant Professor.

May 24, 2014

Prof. Mahapatra has conducted ‘Art of Compact Modeling’ workshop at IIT Gandhinagar during 12 to 21st May under its Knowledge Network program (http://www.iitgn.ac.in/kn/)

May 16, 2014

Dr Pujarini Ghosh has received Kothari Post-Doc fellowship from University Grant Commission.

May 15, 2014

Our paper “Germanane : a ‘Low Effective Mass’- ‘High Bandgap’ 2-D Channel Material for Future FETs” has been accepted for publication in IEEE Transactions on Electron Devices. In this paper, through ab-initio simulation, we discussed the possibility of using the Germanane as a channel material for conventional and tunneling field effect transistors for two different morphologies viz. chair and boat.

May 7 2014

Neha Sharan has received DST travel grant to present her paper in Workshop of Compact Modeling, Washington DC.

April 15, 2014

Dr. Jandhyala Srivatsava has joined the Centre for VLSI and Embedded System Technologies, IIIT Hyderabad as an Assistant Professor.

Neha Sharan has received Sarukkai Jagannathan Award from the Institute as a support for travel expenditure for attending and presenting paper in conferences.

March 7, 2014

Dr. Jandhalya Srivatsava has received the Tag Corporation Medal 2013, which is given for the best research thesis from the department every year. He was involved in developing the core of indDG compact model. He received Post Doc fellowship from BSIM compact modelling group, UC Berkeley.

Our paper “Performance Analysis of Boron Nitride Embedded Armchair Graphene Nanoribbon MOSFET with Stone Wales Defects” is accepted for publication in Journal of Applied Physics. In this paper we study the performance of a Boron Nitride embedded Graphene armchair nanoribbon channel based MOSFET characteristics by DFT-NEGF technique. We also demonstrate the effect of the stone wale defects on transistor characteristics.

December 6, 2013

Rekha Verma has successfully defended her PhD thesis entitled as “Investigation of electro-thermal and thermoelectric properties of carbon nano materials”. Her work has resulted in several publications in IEEE and other journals.

November 22, 2013

Our paper “Monolayer Transition Metal Dichalcogenide Channel Based Tunnel Transistor, has been accepted for publication in the open access IEEE Journal of the Electron Devices Society.In this paper we study the real and imaginary band structure of MX2 materials by density-functional theory (DFT), which is then used to evaluate the gate-controlled tunnelling current under the WKB approximation. Further, we also demonstrate the strain effect on the complex band structures and the performances of MX2 based TFETs.

November 18, 2013

Our paper “Continuity Equation Based Nonquasi-static Charge Model for Independent Double Gate MOSFET” has been accepted for publication in Journal of Computational Electronics. In this paper we have shown how the ‘piecewise charge linearisation technique’ that we proposed for quasi-static charge modelling could be extended under nonquasi-static situation.

November 12, 2013

Our paper “Negative differential resistance and effect of defects and deformations in MoS2 armchair nanoribbon MOSFET” has been accepted for publication in the Journal of Applied Physics. In this paper, using DFTB, we have analysed the effects of different mechanical deformations (twist, ripple etc.) on a monolayer MoS2 nanoribbon based ultra-short-channel MOS transistor.

October 29, 2013

Ramkrishna Ghosh has joined Prof. Suman Datta’s group at Penn-State University as a post-doc fellow.

August 21, 2013

Ram Krishna Ghosh has successfully defended his PhD thesis entitled as “Exploration of real and complex dispersion relationship of nanomaterials for next generation transistor applications”. His work has resulted in several publications in IEEE and other journals.

August 16, 2013

Based on the concept of controlling the phonon movements in a single layer degenerate graphene sheet by C13 isotope doping (see our paper in IEEE T-ED June 2013) we have applied for an Indian patent entitled as “A graphene based thermoelectric generator” (3625/CHE/2013).

August 16, 2013

Ms Madhuchhanda Brahma has joined our lab as project associate. She did her M.Tech. in VLSI Design from Bengal Engineering and Science University, Shibpur.

August 5, 2013

Ms. Rekha verma has submitted her Ph.D Thesis for evaluation. Sheworked on the investigation of electro-thermal and thermoelectric properties of carbon nanomaterials.

July 29, 2013

Our paper “Solution of Time Dependent Joule Heat Equation for a Graphene Sheet under Thomson Effect”, has been accepted for publication in the IEEE Transactions on Electron Devices. In this paper we demonstrate that the temperature in an isotopically-pure (containing only C12) SLG sheet attains its saturation level quicker than when doped with its isotopes (C13). These results have been formulated using the electron interactions with the in-plane and flexural phonons to demonstrate a field dependent Landauer transmission coefficient.

26 Jul 2013

Mr. Dipankar Saha has joined our lab as project associate. He did his M.Tech. in VLSI design and microelectronics technology from Jadavpur University in 2013.

24 Jul 2013

Dr. Pankaj Kumar Thakur has joined IIT Ropar as an Assistant Professor. In his Ph.D. thesis, he worked on different compact modelling aspects of independent double gate MOSFET. He was a post doctoral fellow in BSIM group at UC Berkeley.

July 13, 2013

Our paper “Performance Analysis of Strained Monolayer MoS2 MOSFET”, has been accepted for publication in the IEEE Transactions on Electron Devices. In this paper using our in-house NEGF simulator we have studied the performance of monolayer MoS2 MOSFET under uniaxial and bi-axial strain at their ballistic limits.

July 4, 2013

Our paper “Proposal for Graphene-Boron Nitride Heterobilayer Based Tunnel FET”, has been accepted for publication in the IEEE Transactions on Nanotechnology. In this paper, by analyzing the complex bandstructure, we demonstrate the possibility of using Graphene-Boron Nitride Heterobilayer channel for high performance Tunnel FET application.

June 18, 2013

Our paper “”Modeling of Temperature and Field Dependent Electron Mobility in a Single Layer Graphene Sheet” has been accepted for publication in IEEE Transactions on Electron Devices. In this work we address a physics-based analytical model of electric field dependent electron mobility in a single layer graphene sheet using the formulation of Landauer and Mc Kelvey’s carrier flux approach under finite temperature and quasi-ballistic regime.

June 3, 2013

Mrs. Pujarini Ghosh has joined our lab as a Research Associate(RA),PhD in Microelectronics from University of Delhi, South Campus, New Delhi.

Neha Sharan has been selected by the CEFIPRA for participating in the ESONN Session 2013 (“http://esonn.fr”). Only six Indian students’ participation will be supported by the CEFIPRA for this school.

May 9, 2013

Our paper “Non-Quasi-Static Charge Model for Common Double-Gate MOSFETs Adapted to Gate-Oxide-Thickness Asymmetry” accepted for publication in IEEE Transactions on Electron Devices. In this paper we extend this concept of quasi-linear-relationship of the surface potentials, which was earlier used to develop Quasi-Static charge model of indDG, to develop continuity equation based non-quasi-static (NQS) charge model.

May 1, 2013

Our paper “Performance limits of transition metal dichalcogenide (MX2) nanotube surround gate ballistic field effect transistors” has been accepted for publication in Journal of Applied Physics. In this paper, through DFT and NEGF formalism we have analysed and compared the characteristics of different MX2 nanotube based MOS transistors at their ballistic limit.

April 30, 2013

Mr. Ramkrishna Ghosh has submitted his Ph.D. thesis for evaluation. In this thesis he studied the real and imaginary dispersion relationship of nano materials for their possible application in next generation transistors.

April 12, 2013

Pankaj Kumar Thakur has successfully defended his Ph.D. thesis.

April 11, 2013

Our paper “Thermoelectric Performance of a Single Layer Graphene Sheet for Energy Harvesting” has been accepted for publication in IEEE Transactions on Electron Devices. In this paper, for the first time, we demonstrate the immense potential of Graphene for “in chip” waste heat recovery application.

March 6, 2013

Dr. Sitangshu Bhattacharya has joined School of Engineering, Shiv Nadar University as an Assistant Professor. His long association with our group had resulted in several significant publications.

February 27, 2013

J. Srivatsava has successfully defended his Ph.D. thesis. Currently he is working as a Post Doc in BSIM group at UC Berkeley.

February 13, 2013

Aby Abraham has received ‘Alumni Medal’ for the academic year 2011-2012 for his excellent performance in M.E. Microelectronics program. He worked on compact modelling issues of independent double gate MOSFET, which has resulted in three IEEE T-ED publications.

January 31, 2013

Dr. Arkaprava Bhattacharya has joined our lab as research associate. He received his Ph.D. from IMS lab of University of Bordeaux 1, France. In his PhD work he had examined Non quasi static effect in SiGe HBT using physical device simlation (Sentaurus) and compact modeling (HICUM).

Dr. Amretashis Sengupta has been invited to deliver a talk in CeCAM workshop at Bremen Center for Computational Materials Science. Check Here

December 3, 2012

We have received funding from the Department of Science and Technology (DST), Government of India, to conduct research on 2-dimensional material based MOS transistors.

November 13, 2012

Dr. Surya Shankar Dan, first PhD graduate from our lab, has joined EE Department of IIT Hyderabad as an Assistant Professor.

November 6, 2012

Our paper “k.p based closed form energy band gap and transport electron effective mass model for [100] and [110] relaxed and strained Silicon nanowire” has been accepted for the publication in Solid State Electronics. In this paper, we address a physics based closed form model for the energy band gap and the transport electron effective mass in relaxed and strained [100] and [110] oriented rectangular Silicon Nanowire (SiNW). The proposed analytical model are based on the k.p formalism and has been found in good agreement with tight binding sp3d5s* method based numerical simulations. Such models are useful for SiNW based device design.

November 3, 2012

Our paper “A physics based flexural phonon dependent thermal conductivity model for single layer graphene” has been accepted for publication in IOP Semiconductor Science and Technology. In this paper, we address a physics based closed form analytical model of flexural phonon dependent diffusive thermal conductivity of suspended rectangular single layer graphene (SLG) sheet, which found to possess an excellent match with various experimental data over a wide range of temperature. This model could be very useful for an efficient electro-thermal analyses of graphene based interconnect.

October 24, 2012

Our paper “Direct Band-to-band tunneling in reverse biased MoS2 nanoribbon p-n junctions” has been accepted for publication in the IEEE Transactions on Electron Devices. In this paper, for the first time, we explore the possibility of using MoS2 as the channel material for Tunnel FET.

October 22, 2012

J. Srivatsava has joined BSIM group at UC Berkeley as post-Doc student.

October 16, 2012

Our paper “Physics-Based Solution for Electrical Resistance of Graphene under Self-Heating Effect” has been accepted for publication in IEEE Transactions on Electron Devices. In this paper we propose a novel method to estimate the electrical resistance of suspended single layer Graphene by using the solution of the Joule self-heating equation at various current densities and temperatures. This technique is useful in a view of strong interest to thermal conductivity and self-heating effects in Graphene. It can also be used for comparison with recent experiments.

5 October, 2012

Our paper “Bipolar Poisson Solution for Independent Double-Gate MOSFET” has been accepted for publication in IEEE Transactions on Electron Devices. In this paper we propose new IVE (Input Voltage Equation) for compact modelling of asymmetric/independent double gate MOSFET which is valid from accumulation to inversion regime. The existing IVEs are based on unipolar solution of Poisson equation and thus valid only for inversion mode application.

10 September, 2012

Mr. J. Srivatsava has submitted his Ph.D. thesis for evaluation. He worked on Compact Modeling of Independent/Asymmetric Double Gate MOSFETs.

Our paper “Inclusion of the Body Doping in the Compact Models for Fully-Depleted Common Double Gate MOSFET Adapted to Gate-oxide Thickness Asymmetry”, has been accepted for publication in IET Electronics Letters. Here we propose a simple technique to include body doping in indDG core, which was developed for undoped body devices. Proposed technique predicts the current and terminal charges quite accurately as long as the channel is fully depleted.

29 May, 2012

Our paper “Theoretical Estimation of Electro-migration in Metallic Carbon Nanotubes Considering Self-Heating-Effect” has been accepted for publication in IEEE Transactions on Electron Devices. In this paper, probably for the first time, we estimate the solution of the electro-migration diffusion equation (EMDE) in an isotopically pure and impure metallic single walled carbon nanotube (SWCNT) by considering self-heating. The methodologies as presented here can then be put forward for obtaining a fairly well estimation of the electro-migration effects on the next generation CNT based interconnects.

20 April, 2012

Amretashis Sengupta has joined our group as a Research Associate (RAP), PhD in Nanoelectronic Devices, from Jadavpur University, Kolkata.

28 March, 2012

Our paper “Piecewise Linearization Technique for Compact Charge Modeling of Independent DG MOSFET” has been accepted for publication in IEEE Transactions on Electron Devices. This paper generalizes the limitations of conventional charge linearization techniques while modeling the terminal charges of the Independent Double Gate MOSFET, which was earlier noticed by Pankaj in his T-ED paper. The paper also generalizes the channel segmentation concept conceived by Pankaj and propose a much more computationally efficient charge model by introducing the novel concept of primary and secondary input voltage equations (P-IVE and S-IVE). The new model, which preserves the source/drain AC-symmetry (essential for RF circuit design), is successfully implemented in professional circuit simulator.

8 March, 2012

Our paper “Physics based band gap model for relaxed and strained [100] silicon nanowires” has been accepted for publication in the IEEE Transactions on Electron Devices. In contrast to usual computationally intensive numerical techniques, which are available in literature, in this work we propose a physics based simplified analytical model of the energy band gap and electron effective mass in a relaxed and strained rectangular [100] Silicon Nanowires (SiNWs). Our proposed formulation is based on the effective mass approximation for the non-degenerate two band model and 4×4 Luttinger Hamiltonian for energy dispersion relation of conduction band electrons and the valance band heavy and light holes respectively.

15 February, 2012

Prof. Mahapatra has been awarded “Ramanna Fellowship” from the Department of Science and Technology, Government of India as a support for his research activities in the area of compact modeling of multi-gate MOSFETs. First time this award is given to somebody in electrical science discipline.

11 January, 2012

Our paper “A Simple Charge Model for Symmetric Double-Gate MOSFETs Adapted to Gate-Oxide-Thickness Asymmetry” has been accepted for publication in IEEE Transactions on Electronic Devices. This paper proposes an analytical technique to handle the gate oxide thickness asymmetry in a FinFET transistor in a very simple and elegant fashion. Proposed model has been implemented in circuit simulator.

10 January, 2012

Our department name has been changed from “Center of Electronics Design and Technology” to ” Department of Electronic Systems Engineering”.

2 January, 2012

Manikanta, 1st year M.E. Microelectronics student has joined the lab to do his M.E. project. He will be working on Inclusion of Body Doping in Compact Models.

15 December, 2011

Our paper “Improvements in Efficiency of Surface Potential Computation for Independent DG MOSFET” has been accepted for publication in IEEE Transactions on Electron Devices. In this paper we demonstrate some significant improvement in surface potential calculation algorithm that we proposed earlier (IEEE T-ED June 2011). This is a tremendous achievement for Aby Abraham, who is the first author of this paper and currently completing his M.E. program in Microelectronics. Because this two years M.E. program is fully loaded with course work and so the students get very little time to do research.

16 November, 2011

Surya Shankar Dan (Ph.D. student during 2006-2009 ) has won the Tag Corporation Medal 20010-2011, which is given for the best Research thesis in CEDT every year. He analyzed the effect of energy quantization on Silicon Single Electron Transistor devices and circuits. He is currently working as a Post Doc fellow at EPFL, Switzerland.

18 October, 2011

Mr. Pankaj Kumar Thakur has submitted his Ph.D. thesis for evaluation. He worked on compact modeling of independent double gate transistors.

21 September, 2011

Sudipta Sarkar (M.E. Microelectronics student of 2008-2010 batch) has won the best M.Tech thesis award under SMDP-II for academic year 2009-10. It is a national level award conducted by Ministry of Communication & Information Technology. He worked on non-quasi-static modeling of double gate MOSFETs in collaboration with Dr. Ananda Shankar Roy (Intel, Hillsboro). His work was reflected in Solid State Electronics Journal and also in VLSI design conference. Award consist of Rs 1.25 lakh for the laboratory, Rs. 12500 for the supervisor and Rs. 7500 for the student.

19 September, 2011

Our paper “Quantum Capacitance in Bilayer Graphene Nanoribbon” has been accepted for publication in Physica E. In this paper we address a physically based analytical model of quantum capacitance (CQ) in a bilayer graphene nano-ribbon under the application of an external longitudinal static bias. We demonstrate that as the gap about the Dirac point increases, a phenomenological population inversion of the carriers in the two sets of subbands occurs. This results in a periodic and composite os- cillatory behavior in the CQ with the channel potential, which also decreases with increase in gap.

14 September, 2011

Prof Costin Anghel, from ISEP (Institut supérieur d’électronique de Paris) , visited our laboratory. He is our collaborator in a IFCPAR funded project. He delivered an interesting talk on Tunnel Field Effect Transistor.

2 August, 2011

Mr. A. Rex has successfully defended his M.Sc. (Engg.) thesis. He worked on analytical modeling of thermal conductivity of metallic carbon nanotube which is important in next generation carbon based interconnect. His work resulted one IEEE EDL publication. He will join Department of Instrumentation and Applied Physics, Indian Institute of Science as Ph.D. student.

2 August, 2011

Ms Rekha Verma and Ms Neha Sharan have joined the lab as Ph.D. students.

23 July, 2011

Our paper, “Analytical Solution of Joule Heating Equation for Metallic Single Walled Carbon Nanotube Interconnects”, has been accepted for publication in the IEEE Transactions on Electron Devices. In this paper, we address a closed form analytical solution of Joule-heating equation for metallic single walled carbon nanotube (SWCNT). A temperature dependent thermal conductivity ( which we earlier publised in IEEE EDL Feb 2011) has been considered on the basis of second order three phonon Umklapp, mass difference and boundary scatterings phenomena. Our analytical model as presented here agrees well with the numerical solution and can be treated as a method for obtaining an accurate analysis of the temperature profile along the CNT-based interconnects.

1 June, 2011

New course ‘E3-225: Art of Compact Modeling’ will be introduced in August semester. Content of the course is available in Prof. Mahapatra’s homepage.

15 March, 2011

Our paper, “An efficient robust algorithm for the surface potential calculation of Independent DG MOSFET”, has been accepted for publication in the IEEE Transactions on Electron Devices. In this paper we propose an algorithm to solve the IVEs earlier developed by our group (IEEE T-ED March 2010). Efficient solution of IVEs is an important issue for the implementation of surface potential based compact models in circuit simulator. The IVEs of IDG MOSFET are much complicated than bulk or symmetric DG MOSFET as they have several non-removable singularity and discontinuity points. Proposed algorithm, which combines the regular Newton Raphson algorithm with Ridders and Bisection method in an unique way in order to provide assured yet efficient convergence at any bias conditions, is also successfully implemented in commercial circuit simulator. This paper is an example of a good interdisciplinary work between device physics and scientific computation communities.

28 February, 2011

A. Rex has submitted his M.Sc. (Engg.) thesis. He worked on ‘Analytical Thermal Conductivity Modeling for metallic Single Walled Carbon Nanotube’ which might find application in next generation carbon nanotube based interconnects. A part of his work is published in IEEE Electron Device Letters, Feb 2011.

4 January, 2011

Aby Abraham, 1st year M.E. Microelectronics student has joined the lab to do his M.E. project. He will be working on compact modeling of multi gate MOSFETs.

3 January, 2011

Our Ex-lab member Mr. Sudipta Sarkar (M.E. Microelectronics 2008-2010 batch) has joined Dr. Bhaskar Banerjee’s group as a Ph.D. student at University of Texas, Dallas. Prior to that he worked for Rambus, Bangalore for few months.

26 November, 2010

Avinash Sahoo (M.Sc. Engg. student of 2007-2009 batch) has won the Tag Corporation Medal 2009-2010, which is given for the best Research thesis in CEDT every year. His work (which was published in IEEE T-ED March 2010) provides breakthrough solution in the compact modeling of IDG MOSFET and has received several citations. Abstract of his thesis is available in our website.

4 November, 2010

Our paper “Physics Based Thermal Conductivity Model for Metallic Single Walled Carbon Nanotube Interconnects” is accepted for publication in IEEE Electron Device Letters. In this paper, probably for the first time, we propose a temperature dependent thermal conductivity model for metallic CNT, which could be very useful for thermal analysis of next generation CNT based interconnects. It should be noted that thermal conductivity of Cu, which is the present interconnect material, is almost independent of temperature variation. The temperature dependent thermal conductivity of CNT was earlier demonstrated experimentally, but the scattering mechanisms those control this event, were not well understood.

1 November, 2010

Dr. Surya Shankar Dan, the first Ph.D. graduate from our lab, has joined Prof. Adrian Ionescu’s group as Post Doctoral fellow at EPFL, Switzerland.

1 October, 2010

Our paper “Large Signal Model For Independent DG MOSFET”, has been accepted for publication in the IEEE Transactions on Electron Devices. It will be published in Jan 2011 issue. In common compact modeling practice, the terminal charges are expressed as explicit function of the channel inversion charge densities at source and drain end. It works very well for bulk and symmetric DG MOSFETs. In this paper we have shown that in case of IDG MOSFET, it is very difficult to continue such practice when the source end of the channel is in trigonometric mode and the drain end is in hyperbolic mode, as it results in unphysical behavior. Another recent publication on terminal charge modeling also suffers from the same problem. Therefore compact modeling of IDG MOSFET is appearing to be very challenging, as the well-established compact modeling tricks is not working for this device.